Codeigniter Parent Controller with "X-Clacks-Overhead: GNU Terry Pratchett" Header

MY_Controller.php

<?php

/**
 * application/core/MY_Controller.php
 *
 * All application controllers should extend Base_Controller instead of CI_Controller
 */

class Base_Controller extends CI_Controller {
 
    public function __construct() {
   
        parent::__construct();
        $this->output->set_header('X-Clacks-Overhead: GNU Terry Pratchett');
    }
}

?>